Udi, Am 04.02.05, 14:54 +0100 schrieb Udi Fuchs:
> Hi, > > I wrote a small tool that uses DCRaw to read raw images from digital > cameras, and uses LCMS for some basic color management. You can check > it out at: > http://ufraw.sourceforge.net/ nice, would You like to add screenshoots? > I'm trying to keep the user interface simple, but it is a bit > problematic. The problem is that in some cases the raw data has to be > manipulated BEFORE applying the color transformation. You can choose to transform the image in the first place (16-bit or 8-bit as You like) , and do manipulations (Your curves) on the output (16-bit or 8-bit depending what You choose for the colour conversion before). This is state of the art. (I agree with Gerhard Fuernkranz.) For fun, You can load Your image into an image editor. Graphics Magic or CinePaint can handle 16-bit data and more. Then apply (hypothetically) Your curves there and convert the image with an specific ICC profile. This makes it necessary to create one profile for each curves set You apply. It is for the amount of profiling work very unhandy. > For example, the profile for the Nikon D70 (it can be downloaded from > my site) requires a gamma=0.45 curve, this is a naive gamma curve of > pow(x,0.45). Other profiles seem to require a gamma curve which is > linear at the beginning. And some profiles are "linear" in the sense, > that they can be applied to the raw data directly. > > Does someone know if the information on the required "preprocessing" > is embedded somewhere in the ICC profile? All profiles include gamma curves. Maybe You can tweak them. What profiler does You use so You need editing the image first? > I'm amateur at color management, so any other comments on the way I > apply the profiles will be welcome, For instance CinePaint (expect Photoshop does basically the same, Please correct if otherwise): There You can load the 16-bit per channel image (for CinePaint with an minimal dcraw plug-in) and A) automatically convert the raw image to an workspace of choice with Your camera profile and the selected workspace profile, or B) attach the camera profile and leave the image in its native color space - looking at it through the monitor profile. A is the prefered way to edit in an well balanced colour space of You choice. B is useful for minor retoushing and preserving the raw colour space for further processing. > Udi On 5.and 6.march at the Chemnitzer LinuxTage in Germany <http://chemnitzer.linux-tage.de/2005/info/>, I will again demonstrate an fully colour managed workflow under linux at an booth. (in german)<http://chemnitzer.linux-tage.de/2005/live/detail.html?idx=161> Maybe You are not living that far away. The Linux-Bus will bring people from Berlin over Dresden to Chemnitz. For more reading about linux and colour management follow the link below. regards Kai-Uwe Behrmann + development for color management + imaging / panoramas + email: [EMAIL PROTECTED] + CMS proposal <www.behrmann.name> ------------------------------------------------------- This SF.Net email is sponsored by: IntelliVIEW -- Interactive Reporting Tool for open source databases. Create drag-&-drop reports. Save time by over 75%! Publish reports on the web. Export to DOC, XLS, RTF, etc. Download a FREE copy at http://www.intelliview.com/go/osdn_nl _______________________________________________ Lcms-user mailing list [email protected] https://lists.sourceforge.net/lists/listinfo/lcms-user
